Dewatering and coking slurry coal



June 2, 1949. A. F. HowE 474,251

DEWATERING AND coKING SLURRY com.

Filed Dec. 9. 1944 5 Sheets-Sheet 1 June 28, 1949. A. F. HowE DEWATERING AND COKING SLURRY GOAL 3 Sheets-Sheet 2 Filed Dec. 9, 1944 .Fume 28, 1949; A. F. HowE DEWATERING AND GOKING SLURRY COAL 3 Sheets-Sheet 3 Filed D90. 9, 1944 Patented June 28, 1949 DEWATERING AND COKING SLURRY GOAL Anarewr. Howe; st. Louis, M0., assigner to cen'- trifugai 48a Mechanical Industries. Inc., Stb Louis, Mo., a corporation of Missouri Application December 9, 1944, Serial Not 567,496

9 Claims. (Cl. 202-96) This invention relates tothe recovery of sludge vor slurry coal;` and it has special reference to an apparatus and method for`processing sludge or slurry coal' that is usually discarded as useless by coal washeries, in order to remove from vsaid otherwise useless coal a large proportion of the ash, substantially dehydrate or substantially dry f said coal, and thereafter process and treat said substantially dehydrated or dried coal from which said ash had been removed to form an excellent and superior fuel for domestic and other uses.

' An object of the invention is to provide van imsludge or slurry coal, substantially dehydrating i or drying said sludge orslurry coal in measured or in suitable quantities, delivering .measured or suitable quantities ,inproper arrangement and distribution into a devolatilizer, including a heated oven, to remove the volatile from the substantially dehydrated or dried slurry coal and from quantities of small bodies of coal, and converting said otherwise useless coal into an excellent and superior fuel that does not discharge or produce objectionable quantities of obnoxious smoke, fumes and gases during combustion.

Another object of the invention is to provide an improved apparatus for reclaiming and recovering sludge or slurry coal that is usually, and in some localities always, discarded as useless waste, comprising mechanisms for removing the ash and most of the water from the otherwise useless coal, mechanism for distributing said coal onto an endless conveyor operating through a heated oven inorder to separate a desired amount of the volatile content from the coal, and devices for controlling the operation of said mechanisms so that neither continues in operation when the other is inoperative unless desired.

Another object of the invention is to provide an improved apparatus for separating high volatile coal from a mixture of coal and water and thereby substantially dehydrating or drying said coal and also removing a large proportion of thei ash therefrom, and then reducing thev volatile content of said coal to a desired extent to form an excellent and superior fuel that will not dis charge or produce objectionable quantities oi ob- UNITED ASfl'rrrl-:s

2 noxious smoke, fumes and'gases during' combustion. In the attainment of thisobjective, the coal maybe pumped or otherwise conveyed from a sludge tankforlfrom the 'usual large overhead sludge tanks, screened.k and then substantially dehydrated or dried rand. processed to lremove or reduce the volatile "content of the lcoal'to any desired extent, Various other objects and]r advantages will be I*apparent from the following description, refere'nce being'made to the annexeddrawings, 'in

Fig. 1 is a 'vertical longitudinaljsectional view .showing an embodiment'of a devolatiliz'er using fluid fuel such -as gasfor combusion to heat the oven through which ther coal is ycarried by anendless conveyor, portions of the mechanisms 'forsubstantially 'dehydrating or drying the otherwise luseless sludge or slurry c oalbeing shownin'ele? vation. Y. Y

Fig. 2 is a vertical-crosssectional View of a mechanism for 'l'.iistributirigsaid coal in alayer Voi approximately uniform'thickness onto a conveyor, which moves said coal into and through' a devolatilizer which separates a desired amount of -the volatile content from said coal.

Fig. 3 is a horizontal [sectional view of said mechanism on the line 3-`3 of Fig. 2. Y

Fig. 4 is a vertical longitudinal sectional view similar to Fig. 1,'il1ustrating a modification Vof a devolatilizer using solid fuel for combuslon to provide heat for the oven through which the coal is passed, portions of the mechanisms for substantially dehydrating or drying the otherwise useless sludge or `slurry -coal |being shown in elevation. I

Fig. 5 is a relatively enlarged detail view showing the valve device controlling dischargey of substantially measured amounts of sludge or slurry coal into the centrifugal machine for substantially dehydra ting or drying said coal.

Fig. 6 is a side elevation with parts in section showing another modication of the mechanism for removing the ash from, and substantially dehydrating or drying the sludgev or slurry coal preparatory for devolatilization thereof.

Fig. '7 is a diagrammatic view showing the electrical mechanism and connections for controlling proper operation of the apparatus.

Figure 3 is a further diagrammatic View showing the electrical mechanism and connections for controlling the operation of the various machines.

In the embodiment modifications of the invention shown, the sludge or slurry coal in, a hig'hly uent state is discharged, as from a conduit I, onto the upper end of an inclined vibratory screen 2. The screen 2 has a mesh to permit. passage therethrough of the sludge or slurry coal, and small bodies of coal, of a size suitable for further processing according to this invention. The size of the screen mesh required to attain best results may be determined empirically or otherwisaso that most of the water and usable coal will pass through said screen 2 while the oversize solid or rejected fragments are discharged from said screen onto an inclined chute 3 leading to a selected place of disposal. As indicated, the screen 2 is vibrated when in use and during delivery of the coal sludge or slurry thereon. K Vibration may be imparted to said screen under control of electrical mechanism I I0, such as that shown in Fig. 6. It is preferable that said electrical mechanism for vibrating the screen 2 may operate and function only during the time that the mechanism for substantially dehydrating or drying the sludge or slurry coal is in operation, and vice versa, as hereinafter described. The screen 2 may be mounted on pivoted supports 4 which permit free vibratory movements thereof. In the arrangement shown, the supports 4 are mounted on a frame 5.

A tank 6 receives the fluent sludge and slurry and the usable coal passing through the vibrating screen 2. Said tank 8 is supported by the frame 5 or otherwise below the screen 2 and may be open at the top in order to receive the sludge and slurry and the usable coal passing through the screen 2. The bottom of the tank 6 is formed with an outlet passage controlled by a valve I which is operated to open and to close said outlet passage intermittently and thereby permit substantially equal or measured amounts of fluent sludge or slurry and usable coal to pass said valve at intermittent and` spaced intervals.

A shaft 8 for operating the valve 1 and also an agitator device extends for rotation through the lower portion of the tank 6 above the bottom thereof and above the valve 1. In the modification shown, the shaft 8 is constantly rotated during use of the apparatus, and controls opening and closing of the valve l. However, this arrangement of these parts may be varied as desired without departure from the nature and principle of this invention, As shown, the shaft 8 is constantly rotated by a motor 9, although said shaft 8 may be otherwise rotated. Connections I0 operated or controlled by said shaft 8 open and close the valve I intermittently and at spaced intervals in order to discharge and permit passage from the tank 6 of substantially measured amounts of sludge or slurry and usable coal into a chute or passage II. One wall of the chute or passage II may be provided with louver devices I2 through which the sludge or slurry and usable coal passing through said chute or passage may be visually observed and examined to determine the character and quality thereof.

The contents of the tank 6 rise to the level I3. A portion of the contents flows from the tank 6 through an outlet pipe or conduit I4. In the apparatus shown in Figs. l and 4, the outlet pipe I4 opens into the upper end of a clarier mechanism I5. Arms I6 constituting an agitator device are attached to the shaft 8 and are located inside the tank 6, and prevent settling of the lighter particles included in the fluent sludge and slurry, and cause said lighter particles to rise to the level I3 and pass out with a part of the water into and through the pipe or conduit I4 to the clarifier I5. Thus, the mechanism associated the tank 6 in substantially measured quantities comprises a centrifugal machine enclosed within a housing I'I. Said machine, which is shown generically, may be of the type disclosed in either of my prior patents No. 2,043,662, or No. 2,043,663, both dated June 9, 1936; or said machine may be of any preferred construction and design. It is known that sludge or slurry coal delivered into either of said centrifugal machines while said machine is operating will be substantially dehydrated or dried. The usable coal is discharged downwardly from said centrifugal machine upon an apron or passage I8, while the water and finer mesh impurities are discharged from said machine as waste with the eilluent through an outlet passage I9 shown as opening into the outlet or conduit I4 for discharge into the clarifier mechanism I5. The clarier mechanism I5 may be substantially like that disclosed in my prior patent No. 2,218,532, granted October 22, 1940, or of other preferred construction and design. It is known that said clarifier mechanism is operative to clear the water from most of the impurities carried thereby and to condition said water for reuse.

The mechanisms described are cooperatively arranged substantially as disclosed in my prior patent No. 2,305,966, granted December 22, 1942.

My present invention provides means whereby,

the centrifugal mechanism is operated by driving connections 20 only when the clarier mechanism I5 is operated by driving connections 2|, and only during the time that the valve mechanism 'I-III and agitator device 8-I6 are in operation, and vice versa.

The usable coal that is recovered from the sludge or slurry coal, or small bodies and particles of coal, and is substantially dehydrated or dried by the mechanism I'I, passes from said mechanism through a conduit or conveyor 22 to a mechanism for distributing or spreading said coal preparatory for placement upon a conveyor in a devolatilizing apparatus in a layer of approximately uniform thickness. Said distributing and spreading mechanism is operative within an enclosure formed by an enclosing wall 24. Tre substantially dehydrated or dried usable sludge or slurry coal, or small bodies and particles of coal,

may be delivered to said distributing and spreading mechanism otherwise than through the conduit 22 leading from the mechanism I'I. A horizontal shaft 25 extends longitudinally through the elongated horizontal enclosure formed by said wall 24 and carries two oppositely disposed screwlike flanges 26 and 21. The conduit or conveyor 22 discharges the substantially dehydrated or dried usable coal into the enclosure formed by the wall 24 at and along adjacent ends of the screwlike flanges 26 and 2`I and between outlet openings 28 and 29 from said enclosure. The shaft 25 is positively rotated in the direction of the arrow 30, which is in a counter-clockwise direction as shown in Fig. 2. The shaft 25 is rotated only when the mechanism II is operating. My present invention provides means whereby the distributing and spreading mechanism 25-26--21 is operated by driving connection only when said mechanism Il is operating; and, in the -screen 2, of the valve 1, and of the agitator device 6-I6, whenever said mechanism 25-26-21 cannot be operated, or is not in operation. The substantially dehydrated or dried usable sludge or slurry coal, or small bodies and particles of coal, delivered to said mechanism 25-26-2-1 from the conduit 22, or otherwise, is fed and dis- Y tributed or spread laterally in opposite directions by the oppositely disposed screwlike flanges 26 and 21, and is discharged downwardly through a conduit 3 I- 'I'he conduit 3| discharges said substantially dehydrated or dried usable sludge or slurry coal, or small bodies and particles of coal, into a horizontally elongated hopper 32 from which said coal is distributed and deposited in a layer of approximately uniform thickness on an endless conveyor 33 forming part of a devolatilizing apparatus. The coal is delivered onto said conveyor 33 in controlled and substantially measured quantities through a narrow chute 34 having a lateral horizontal length approximately equal to the lateral horizontal length of the hopper 32 and the lateral horizontal width of the conveyor 33. That is to say, the lower discharge opening 35'at the lower end of the chute 34 extends nearly the full width of the conveyor 33.

Measured quantities of substantially dehydrated or dried usable sludge or slurry coal, or of small bodies and particles of coal, delivered into the hopper 32 from the distributing and spreading device 25--26-21 are moved from said hopper 32 and discharged onto the conveyor 33 automatically and as an incident to operation of the devolatilizing apparatus. A rotary shaft 36 extends horizontally across the communication from the hopper 32 to the chute 34 approximately equidistant from the front and rear walls of said hopper. The shaft 36 is rotated by driving connections, Aoperation of which is dependent upon operation of the conveyor 33; that is, the shaft 36 cannot be rotated while the conveyor 33 is stationary, or is not operating. A series of radial Walls 31 are attached to the 'shaft 36 and cooperate with the front and rear Walls of the hopper 32 to form measuring compartments 38, Said measuring compartments respectively receive and move quantities of substantially dehydrated or dried usable sludge or slurry coal, or of small bodies or particles of coal, from the hopper 32 during rotation of said measuring device 36-31,

and successively discharge said quantities onto the conveyor 33 in a layer of approximately uniform thickness. The measuring device 36-31 controls passage of coal to the conveyor 33, and is rotated only when this conveyor 33 is in motion under control of one of the operating and supporting shafts 39 for said conveyor.

Both modifications of devolatilizer shown, of which the conveyor 33 forms a part, comprise substantially the same parts and elements as the devolatilizers disclosed in my copending application Serial No. 540,512, now Patent No. 2,406,077 dated August 20, 1946, filed June 15, 1944, of which results, as the two modifications of devolatilizer disclosed in said Patent No. 2,406,077. The devolatilizer shown in Fig. 1 uses fluid fuel such as gas for combustion to heat the oven 40 through which the conveyor 33 passes to carry the layer of substantially dehydrated or dried sludge or slurry coal, or small bodies and particles of coal, placed on said conveyor, in a layer of substantially uniform thickness by the measuring device 36-31. In said apparatus. the oven 40 is above the tcp walls 4I of combustion chambers 42, and is heated by combustion of fluid fuel or gas supplied to burners 43 mounted in said combustion chambers. As disclosed in said Patent No. 2,406,077, a desired amount of the volatile content is separated from the coal within the oven 40, is withdrawn from said oven through an outlet passage 44 by operation of a vacuum pump 45, and is delivered into a receiving tank 46 enclosed in the devolatilizing apparatus. From said tank 46,

combustible gas is conducted to the burners 43 through a conduit pipe 41; so that, as disclosed in said application, the combustible volatile or gas removed from the coal is used for combustion to supply heat to the oven 40'. An additional amount of combustible gas may be supplied to the tank 46 through a pipe 48 leading from an outside source of supply and suitably controlled so that no fuel gas can be supplied to the burners 43 through the pipe 48 when the apparatus forming the present invention is not in use.

The conveyor 33 is operatively supported by a series of four shafts 39 one of which is positively operated by a motor (such as the motor 12, Fig. 7) in order to operate the conveyor 33 positively, and thereby rotate the three other shafts 39. As disclosed in my said application, air is admitted into the enclosure formed by the enclosing wall 52 of the devolatilizer through an air inlet device 53 to replenish air in said devolatilizer caused by withdrawal of air and volatile content Afrom the oven 40. The combustion chambers 42' are hermetically sealed from the oven 40 and from the space enclosed by the wall 52, and that air necessary for combustion is admitted to said chambers from the outside. Air admitted through the air inlet device 53 is preferably substantially free from oxygen and will not air or promote combustion or explosive forces. For this purpose, the air inlet 53 may open directly from the flue 53 that is in communication with and conducts burnt gases from the combustion chamber 42, as indicated generally in Fig. 4.

As disclosed in my said application, the devolatilized layer of coal on the conveyor 33, after said layer of devolatilized coal has passed through and beyond the oven 40, may be formed and compressed into solid bodies or briquettes 54 by a mechanism 55 operated by the motor 12 (-Fig. 7) The briquettes 54 are discharged or caused to drop from the conveyor 33 into a chute 56. From lthe measuring device 36-31 and rotated by the motor the instant application is a continuation in part. l

The` devolatilizer shown in Fig. 4 differs materially or substantially from the devolatilizer above described only in the particular that said devolatilizer of Fig. 4 comprises chain grate stokers 59 operating in and through the combustion chambers which also contain burners 60 to which gas and combustible volatile contentis conducted from the tank 46 through a pipe 7 conduit 6|. The chain grate stokers 5S are arranged and are mounted like the chain grate stokers disclosed in my said application Serial No. 540,512, and are operated by usual chain grate stoker mechanism now generally and commercially available. Operation of the control and agitator mechanisms 1-9--8-I6, the dehydrating or drying mechanism I1, the clarifier mechanism l5, the distributing and spreading mechanism --26--21, the measuring mechanism 36-31, and the mechanisms for operating the conveyor 33 may be coordinated with the chain grate stoker mechanism in any known manner. In localities in which fuel gas is available from outside sources, said fuel gas may be supplied to the tank 46 through a conduit 63. In localities in which fuel gas is unavailable, the conduit 63 may be permanently closed or omitted. In such localities, I prefer to retain the burners and the conduit 6| for conducting from the tanks 46 in the devolatilizer shown in Fig. 1, have the same mode of operation, are for the same purposes, and attain the same effects and results. For these reasons, like reference numerals are applied to like parts in Figs. l and 4.

In the modification shown in Fig. 6, the clarifier mechanism I5 is omitted.. In this modication, the overfiow and skimmer conduit I4 leads to a selected place of discharge other than the clarifier I5. The outlet passage I9 which conducts water from the centrifugal machine I1 for discharge into the clarier I5, is also omitted, or is diverted toward a selected place of discharge instead of toward said clarier. A separate conduit 64 may be provided for conducting water from said centrifugal machine I1 to any chosen place of disposal. From this, it will be seen that the clarier |5 may be used or not, as desired.

Fig. 5 discloses means for optionally controlling operation of the valve 1, and forregulating intermittent operation of said valve by the agitator shaft 8, even while the mechanism I1 is in operation. As shown, an eccentric 65 is mounted on said shaft 8 in a manner to leave said eccentric stationary while said shaft is rotated by the motor 9, or is otherwise rotated. Speed reducing gearing of known construction and arrangement enclosed within a housing 66, constitutes means for rotating the shaft 8 and thereby the eccentric 65 by the motor 8 at relatively slow speed. A clutch member 61 is splined for sliding movements along the shaft 8, and for rotation by said shaft Whenever said shaft is rotating. A lever 68 engages the clutch member 61 and is operative to slide said clutch member along the shaft 8 into and out of clutching engagement with the eccentric 65. When said clutch member is in engagement with said eccentric, the latter will be rotated by the shaft 8lwhenever said shaft 8 is rotated. The connections I8 are engaged with the eccentric 65 in a manner to be operated by said eccentric durcession switches.

erate until they are substantially empty and are free of practically all coal deposits therein. That is to say, the centrifugal mechanism I1, the distributing or spreading mechanism 25--2 6-21, the measuring device 36-3`|. and the conveyor 38, may continue to operate until practically all coal deposits contained in or on said mechanisms and parts are discharged therefrom, and said mechanisms or parts are substantially clear.

Fig. 7 diagrammatically shows the arrangement of the remote controlled magnetic controls from the manually operable master switch 68 through succession switches in the series with the three-phase motors controlled by said suc- That is, the switch 18 shown in Fig. 7 typifies the switch 1| and the other switches controlled thereby. Each of the motors 12, 13, 14, 15, 16, 8 and 18 preferably used in the invention containing the clariiier mechanism I5,

is a three-phase` induction motor. It is to be understood that 'the motor 15 is omitted from the invention shown in Fig. 6 because the clariiier mechanism I5 is omitted from that embodiment of the invention. Referring first to the threephase motor 12, the three leads 19 therefrom are electrically connected with respective contacts attached to a movable bar 8| and preferably composed of insulating material. The contacts 80 are spaced and insulated from each other on said bar and are movable thereby into and out of contact with stationary contacts 82 electrically connected with wires .83, 84 and 85, respectively. When the switch 69 is closed (assuming that the switch 88 remains closed), an electro-magnet 81 is energized and the coreI 88 of said electro-magnet is moved thereby. The core 88 is attached to the insulated bar 8| to which said contacts ing rotation of the latter in order to open and close the valve 1 intermittently. Thus, the shaft 8 may be caused to open and to close the valve 1 intermittently and to permit the sludge or slurry containing usable coal and small particles of coal to ilow past said valve 1 into the chute or passage II, and thence into the mechanism I1. Or, the valve 1 may be left in closed position while said centrifugal mechanism I1 and the remaining cooperating parts of the apparatus continue to op- 88 are secured. When the electromagnet 81 is deenergized, the contacts 80 are spaced from the complementary contacts 82, leaving the circuit to the motor 12 through the conductors 19 open. When the bar 8| is moved by energization of the electro-magnet 81, the contacts 80 are moved into engagement with the complementary contacts 82,

` thereby closing the circ-uit to the motor 12 and energizing and operating said motor. Energize.- tion of the electro-magnet 81 is controlled by the switch 69 and by a switch 86 (previously mentioned), both of which must be in closed adjustment in order to energize said electro-magnet, and opening of either of which deenergizes said magnet and stops the motor 12. This is because of the arrangement in which the lead 89 from the switch 69 is electrically connected with the stationary contact v9|), and because the lead 8| from the switch 86 is connected with one end of the electro-magnet 81, while the other lead 92 from said switch 86 is connected with a contact 93 on the bar 8| for movement into and out of engagement with said contact 88.

The bar 8| supports another contact 94 in alinement with and insulated from all of the contacts 88 and 93 and complementary to a stationary contact 95 analogous to the contacts 82 and 90. The movable contact 94 has electrical connection 86 with one end of an electro-magnet magnet 91 moves the core |03 which is connected with the bar |02 and thereby engages the contacts with complementary stationary contacts |04 having electrical connection with the wires 83, 84 and 85, respectively. The lead |05 from one side of the switch 99 is connected with a contact |06 on the insulation bar |02 for movement into and out of engagement with the stationary lcontact |01 concurrently with the movement of the contacts IOI into and out of engagement with the contacts |04. It is evident that both switches and 99 must be closed before the motor 13, or any of the motors 14, 15, 1B, 9 or 18 in the series can be started; and that opening of either switch 10 or 99 deenergizes the electro-magnet 91 and permits movement of the bar |02 to break electrical communication between the contacts IOI and the complementary contacts |04, and also between the contacts |06 and |01. Electrical communication between the contacts |08 and |09 is eiected by movement of the bar |02 by the electromagnet 91-I03 in the same manner that electrical communication between the contacts 94 and 95 is controlled by movement of the bar 8| by the electro-magnet 81-88. This electrical control connection between the motor 12 and the motor 13 is the same as that between said motor 13 and the three-phase motor 14; and is duplicated between said motor 14 and the three-phase motor 15, and so on through the three-phase motors 16 and 9 to the three-phase motor 18. In the case of the motor 18, the contacts |08 and |09 are omitted from its control, since it is the nal motor controlled.

My invention requires operation of the conveyor 33 during the time in which coal is being delivered thereto from the measuring device 36-31-38. My invention also requires initiation of operation of the measuring device 36-31-38 before initiation of operation of the distributing mechanism 25-26-21, or of the centrifugal machine I1, or of the motor 9 and the parts controlled thereby, or of the vibrator device IIO for the screen 2. That is, my invention requires initiation and maintenance of operation of the conveyor 3 3 before operation of any of said mechanisms 36--31-38, or 25-26-21, or I1, or 9, or IIO, can be initiated. It is evident that delivery of coal through the screen 2 and through the valve 1 into the centrifugal machine I1 while said centrifugal machine remained unoperated would clog said centrifugal machine. It is also evident that operation of the motor 9 and parts controlled thereby and concurrent operation of the centrifugal machine I1 while the spreader mechanism 25-26-21 remained unoperated, would clog said spreader mechanism; or if said spreader mechanism operated concurrently with said centrifugal machine I1 and with the motor 9 while the measuring device 36-31-38 remained unoperated, said measuring device would become clogged. And, finally, it is evident that if said measuring device 36-31-38, and said distributlng device 25-25-21, and said centrifugal machine I1, and said motor 9, etc. operated concurrently while the conveyor 33 remained stationary and unoperated, said conveyor would be overloaded and clogged at the mouth 35 of the chute 34 and no useful result would be attained. Therefore, it is necessary to initiate and maintain operation of the conveyor `33, the measuring device 36-31-38, the distributing device 25-26-21, the centrifugal machine I1, the motor 9 and parts controlled thereby, and the vibrator mechanism 10 ||0, in the order stated, to attain best results, or even to attain useful results. However, I contemplate operatingA the vibrating mechanism IIO forthe screen 2 independently.

5 The motor 12, diagrammatically shown in Fig. 8, is connected to operate one of the shafts 39, and thereby the conveyor 33, and also the mechanism 55 in any known or approved manner within the skill of the mechanic, or as disclosed l0 in my said patent No. 2,406,077. The motor 13 is connected to operate the shaft 36 of the measuring device 35-31-38; the motor 14 is connected to rotate the shaft 25 of the spreader device 25-26-21'; the motors 15 and 16 are connected to operate the clarier mechanism I5 and the centrifugal machine I1, respectively, althougla the motor 15 will be omitted when the clarier mechanism I5 is not used in the assembly; the motor 9 is connected to operate the valve 1 controlling passage of sludge or slurry coal through the chute II into the centrifugal machine I1 and also to operate the agitator 8-I6.

The inclusion of mechanism not herein disclosed, making operation of the conveyor 33 and burners 43 interdependent; or making interdependent operation of said conveyor 33 and the chain grate stokers 59, is contemplated, and said inclusion of said mechanism does not constitute departure from the nature and principle of the invention as disclosed herein. I contemplate such other and further variations without departure from the nature and principle of the invention as may be within the scope of the appended claims.

I claim:

1. An apparatus for recovering sludge or slurry coal, comprising a machine for separating water from said coal, a device for receiving said coal i, from said machine and for spreading said coal 4U preparatory for the reduction of the volatile content thereof, a relatively wide conveyor for supporting and moving a layer of said coal through an oven for reduction of the volatile content thereof, operating mechanismfor moving said conveyor, and mechanisms controlled by said operating mechanism for operating said machine and said device,- respectively, during operation of said operating mechanism only.

2. An apparatus for recovering sludge or slurry coal, comprising a heated oven for reducing the volatile content of said coal as desired, a relatively wide conveyor for supporting and moving a layer of said coal through said oven for reduction of the volatile content of said coal as aforesaid, a, measuring device for successively delivering a layer of measured quantities of said coal onto said conveyor outside of and for movement through said oven, a spreader for spreading and delivering said coal to said measuring device for delivery onto said conveyor as aforesaid, mechanisms for operating said measuring device and said spreader, respectively, a machine for separating water from said coal and for delivering said coal to said spreader for delivery to said measuring device and thence to said conveyor, and operating mechanism for moving said conveyor and said layer of coal thereon through said oven and preventing operation of said measuring device and said spreader and said machine when said last named mechanism is unoperated.

3. An apparatus for recovering sludge or slurry coal, comprising a heated oven for reducing the volatile content of saidcoal, a relatively wide conveyor for supporting and moving a layer of said coal through said oven to reduce the volatile content of said coal as aforesaid, a machine for separating water from said coal preparatory for delivery of said coal onto said conveyor, devices between said machine and said conveyor for spreading and delivering a layer of measured quantities of said coal onto said conveyor only when said conveyor is moving, mechanism for operating said devices and said machine, respectively, and operating mechanismior moving said conveyor and said layer of coal thereon through said oven and for preventing operation of said machine and said devices when said last named mechanism is unoperated.

4. An apparatus for recovering sludge or slurry coal, comprising a relatively wide movable conveyor, rotary shafts for supporting and moving said conveyor, mechanism for positively rotating one of said shafts and thereby moving said conveyor, a measuring device for successively delivering measured quantities of coal onto said conveyor when said conveyor is moved as aforesaid, means for operating said device to deliver successively said measured quantities of coal onto said conveyor, and elements controlled by said mechanism preventing operation` of said means and thereby preventing operation of said measuring device during the time that said mechanism is unoperated.

5. An apparatus for recovering sludge or slurry coal, comprising a heated oven for devolatilizing said coal, a relatively wide conveyor for supporting and moving said coal through said oven for devolatilization, a measuring device for delivering a layer of said coal onto said conveyor outside of and for movement through said oven, a spreader for spreading and delivering said coal to said measuring device for delivery onto said conveyor as aforesaid, mechanisms for operating said measuring device and said spreader, respectively, and mechanism for moving said conveyor through said oven and for preventing operation of said mechanisms for operating said measuring device and said spreader when said last named mechanism is unoperated.

6. An apparatus of the character described, comprising a device for separating water from sludge coal and from slurry coal, a heated oven for reducing the volatile content of said coal after said water has -been separated therefrom by said device, a relatively wide conveyor for supporting and moving through said oven a layer of said coal during reduction of the volatile content thereof as aforesaid, mechanism for delivering said coal that has passed from said device onto said conveyor in the form of a layer for movement through said oven, mechanisms for operating said device and said rst named mechanisms, respectively, and operating mechanism for said conveyor controlling operation of said mechanisms for operating said device and said first mechanism. n

7. An apparatus ofthe character described, comprising a device for separating water from sludge coal and from slurry coal, a relatively wide conveyor for supporting and moving a layer of said coalduring reduction of the volatile content said 'coal by said device, means for delivering onto said conveyor a layer of said coal from which water had been separated by said device as aforesaid, mechanisms for operating said device and said means and said conveyor, respectively, and means controlled by one of said mechanisms preventing operation of any of said other mechanisms during the time that said one mechanism remains unoperated.

8. An apparatus of the character described, comprising a device for separating water from sludge coal and from slurry coal, means for controlling delivery of said sludge coal and said slurry coal into said device for separation of said water from said coal, a relatively wide conveyor for supporting and moving a layer of said coal passing from said device during reduction of the volatile content of said coal, devices for receiving said coal from said first device after said water has been separated therefrom, operating mechanisms for operating said first. device and said means and said conveyor and said last named devices, respectively, and means controlling operation of said operating mechanisms for said rst device and said means and said last named devices by said operating mechanism for said conveyor.

9. An apparatus of the character described, comprising a device for separating water from sludge coal and from slurry coal, means for controlling delivery of said sludge coal and said slurry coal into saiddevice for separation of said water from said coal, a relatively wide conveyor for supporting and moving a layer of said coal passing from said device during reduction of the volatile content of said coal, devices for receiving said coal from said first device after said water has been separated therefrom, operating mechanisms for operating said first device and said means and said conveyor and saidlast named devices, respectively, means controlling operation of said operating mechanisms for said first device and said means and said last named devices by said operating mechanism for said conveyor, and mechanism cooperating with said conveyor for forming said coal into solid bodies after the volatile content of said coal has been reduced as aforesaid.

ANDREW F. HOWE.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 289,718 Schaefer Dec. 4, 1883 974,919 Richards et al Nov. 8, 1910 1,420,165 Trent June 20, 1922 1,496,054 Illingworth June 3, 1924 1,522,985 Tail? Jan. 13, 1925 1,824,326 Broadridge Sept. 22, 1931 2,227,951 Wallace Jan. 7, 1941 2,305,966 Howe Dec. 22, 1942 2,332,688 Bailey Oct. 26, 1943 FOREIGN PATENTS Number Country Date 526,386 7 Germany June 8, 1931 

